Mary Riddell is a columnist and a political interviewer for the Daily Telegraph. She writes on topics ranging from family to foreign policy and is particularly interested in criminal justice. Her focus is what is going on, for better or for worse, in the Parliamentary Labour Party.

David Cameron is right about the prison camp of Gaza. Now for some boldness on detainees at home

Good for David Cameron. Gaza is indeed a prison camp, and the PM is right to say so. Naturally, his remark will be seen as inflammatory, particularly given its context. To put down a firm marker against Israel's disgraceful siege of Gaza is one thing. To do so side-by-side with Turkey's Prime Minister Recep Tayyik Erdogan sends an even stronger signal, given the stand-off after the Israelis killed Turkish citizens in their raid on an aid flotilla.

Relations between the countries are at an all-time low, and Mr Cameron was also right to urge a reconciliation. But more importantly, he has indicated that Britain will not humour the Netanyahu government over Gaza. There are some encouraging signs that Mr Cameron, oppportunistic and Europhobic in opposition, may evolve a firmer and more creditable foreign policy than many supposed.

While he is on the subject of prisons, however, I wonder if he might turn his mind to Britain's homegrown hellholes. While those locked up in English jails are not to be compared to the prisoners of Gaza, there is plenty of scope for improvement. As I say in my column today, both Ken Clarke and the Justice Minister, Crispin Blunt, have advanced such pioneering ideas that Labour would be well advised to take them up.

The question is whether Mr Cameron will be as bold and as liberal at home as he is proving, on his Turkish visit, to be abroad.